When Kevin Nelson, University of Kentucky Medical School neurologist and administrator and one of the world's most renowned authorities on near-death experiences, gave a copy of his new book to a good friend who also is his family's spiritual adviser, he told her to please read the epilogue first.
Because that is where the surprise ending is.
In her case, he would rather the ending wasn't a surprise. He wanted her to read his just published book, The Spiritual Doorway In the Brain: A Neurologist's Search for the God Experience (Dutton, $26.95), with the open mind he knows she has and with the grace he knows she feels for all mankind, including him.
In The Spiritual Doorway, Nelson explains "the how" behind everything research subjects and ordinary people have described happening when they believed they went through a gateway into the next life.
The how is not simple, but it has a lot to do with the brain fighting to stay alive a little longer in the absence of enough blood to keep it going.
In the case of near-death experiences, Nelson explains, it's the sudden shifting between states of consciousness — engaging what can only be called borderlands of consciousness — and all the parts of the brain that get abruptly turned off and on when that bump occurs.
Thirty years ago, one of Nelson's first patients, a man named Joe Hernandez, told the young neurology intern that he had just been in the intensive care unit and that he had watched as Jesus and the devil had literally fought over his soul at the foot of his bed.
Jesus had won, the elderly man said, and sent him back to live on Earth for a few more years. Hernandez, so moved by the battle for his essence, had painted a picture of the struggle.
Nelson, also moved, asked a million questions about the fight — what had Hernandez seen and felt and heard — because he wanted to know what was going on in Hernandez' brain at the time of the battle. Hernandez told him, then gave Nelson a picture of the vivid painting.
"I was so enamored and awed by his story that I've kept that picture for 30 years," Nelson says.
Neuroscience had few answers 30 years ago. But it, and Nelson, kept plugging.
Nelson says he had "a conventional career," with board certifications in psychiatry and neurology, electro-diagnostic medicine and clinical neuro-physiology. He is now UK's director of medical affairs.
Yet, all the while, Nelson paid extra attention to studies of near-death experience and the cases of those who described their out-of-body experiences. After all, one in 20 people have out-of-body experiences, a well-known, if not well-publicized fact, says Nelson.
As with Joe Hernandez, Nelson was intensely interested in what was happening in the brains of those with near-death and out-of-body experiences, even those with remarkable spiritual awakening experiences.
Then, one day, while quietly sitting at home in Lexington, Nelson says, he realized something simple but profound: Every night we leave consciousness to sleep, moving to unconsciousness. At some point, we enter an interim state very like what these people are going through, except without the fear or the danger. In those times, we enter a borderland state of consciousness where there is paralysis and visual activation and different parts of the brain are engaged.
It's REM (Rapid Eye Movement) sleep.
In near-death experiences, he theorized, we engage or intrude upon the same parts of the brain that are affected by REM sleep.
Brain's response to crisis
In 2005, Nelson interviewed 55 subjects who thought that they had a near-death experience after enduring heart attacks, car accidents, strokes, near-drowning and other such crises. He compared them with 55 people of the same age and gender who had not had near-death experiences.
What Nelson found was that his subject group was much more likely than the control group to have an arousal system that predisposes them to the intrusion of an REM state on wakefulness, even without the element of impending danger.
He also argues that many of the features of such REM intrusions had correlations to things that those with near-death experiences often talk about. Take the feeling that they are actually dead. In a REM intrusion, the body is paralyzed. Or take the sudden presence of an "unearthly light." In a REM intrusion, that's the activation of electrical waves, or the energizing of the visual brain, something that occurs when the REM switch is flipped.
Other things that dominate the near-death narrative are explainable by the brain's drop in blood pressure during the near-death event, says Nelson. Like the feeling of bliss and lack of pain. "The bright tunnel" so many speak of as seeing or going through, Nelson says, is reminiscent of retinal ischemia, a 5-to-8 second phenomenon that is common even in fainting.
"My conclusion," says Nelson, "is that what happens in the near-death experience is fight-or-flight. It's the way our brain is wired to respond to crisis."
So much for his conventional career.
In the last five years, since his 2005 study, Nelson has been called upon by major media outlets such as CNN, Time magazine, CBS and ABC to talk about the science of near-death experiences. He's been interviewed widely by scientists, paranormalists and skeptics about his theories.
The book will take them on, but mostly with cases and data designed for the smart and curious but non-neurologist who has a passing familiarity with brain jargon. It's not a book aiming to troll the universe of near-death experience, or even to challenge it. It's a book about science, medicine and your amazing brain.
And now the epilogue his friend was supposed to read first.
It makes clear that none of this brain science explains away spiritual experience.
"I am trying to explain brain activity. There is room in the brain for faith," says Nelson, a Protestant whose wife and children are practicing Catholics.
What if, he posits, the same brain paths are used for other purposes as well?
"Even if we could know how every molecule in the brain works, we couldn't explain spirituality. We have the how," he says, "but not the why."
Science and faith can and do coexist, he says.
"The mystery of spirituality lives on."